Embodiments of invention relate to inductor motors and more specifically to speed estimation of inductor motors.
Industrial motors are critical components of industrial applications. Failure of industrial motors not only leads to repair of the motors themselves, but also causes production loss, which usually is more costly than the motor itself. The cost associated with the repair or maintenance of motors can be minimized by closely monitoring the motor's health condition and schedule maintenance in a proactive manner. Therefore, monitoring the health condition of motors during operation is highly desired by the customer to minimize outage and the associate cost with motor maintenance and repair.
Induction motors are one of the most commonly used motors in industrial applications. The most typical failure mode of large induction motors include stator inter-turn fault, broken rotor bar, defective bearing, rotor eccentricity, shaft misalignment, foundation looseness etc. Reliable detection of these failures at incipient stage is critical for the condition monitoring of these motors. In addition to the motor anomaly detection, performance estimation, including the motor's output torque, efficiency, energy usage, etc., is another critical set of parameters to monitor for induction motors. Any trending of these performance related parameters may indicate abnormal condition of the motor's operation.
A rotor speed measurement of induction motor is required by many monitoring and diagnostics modules, such as torque estimation, efficiency estimation, broken rotor bar detection, etc. Furthermore, for closed loop control of induction motors, speed determination is necessary.
Therefore, there exists a need for a system and a method for determining speed of induction motors.